<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>元素定点圆环扩散动画</title>
    <style>
      .container {
        width: 100%;
        width: 500px;
        height: 500px;
        display: flex;
        justify-content: center;
        align-items: center;
        background-color: rgb(87, 121, 231);
      }
      .example-circlekuosan {
        display: flex;
        justify-content: center;
        align-items: center;
      }
      .circle-btn {
        width: 8px;
        height: 8px;
        overflow: hidden;
        background-color: rgba(139, 139, 139, 0);
        border-radius: 100%;
        box-shadow: 0 0 0 0 rgba(214, 214, 214, 0.7);
        cursor: pointer;
        animation: pulsedb 2.25s infinite cubic-bezier(0.36, 0, 0, 1);
      }
      @keyframes pulsedb {
        0% {
          opacity: 1;
          box-shadow: 0 0 0 0 rgba(139, 139, 139, 0.596);
        }
        100% {
          opacity: 0;
          box-shadow: 0 0 0 200px rgba(255, 255, 255, 0);
        }
      }
    </style>
  </head>
  <body>
    <div class="container">
      <div class="example-circlekuosan">
        <div class="circle-btn"></div>
      </div>
    </div>
  </body>
</html>
